Automatic switching mechanism



1, 1932- c. P. SMITH ET AL 1,385,059

AUTOMATIC SWITCHING MECHANISM Filed Oct. 51, 1960 4 Sheets-Sheet lINVENTO 5 'ARLIS 8 SM! H BY EFFREY NEWTDN c. P. SMITH ET AL AUTOMATICSWITCHING MECHANISM Filed Oct. 31,1930 4 Sheets-Sheet 2 no.6 I

INVENTORS CHARLES F. SMITH GOEFFREY NEWTON Nov. 1, 1932.

C. P, SMlTH ET AL AUTOMATIC SWITCHING MECHANISM Filed Oct. 31, 1930 4Sheets-$heet I5 INVENTQRS CHARLES E SMITH ao rmsr uawmm Z QA c. P. SMITHET AL 3 7 AUTOMATIC SWITCHING MECHANISM Patented Nov. 1, 1932 UNITEDSTATES PATENT OFFE CE CHARLES PERCY SMITH AND GEOFFREY NEWTON, OFLONDON, ENGLAND, ASSIGNORS TO INTERNATIONAL STANDARD ELECTRICCORPORATION, OF NEW YORK, N. Y., A

CORPORATION OF DELANABE AUTOMATIC SWITCHING MECHANISM Application filedOctober 31, 1930, Serial No. 492,591, and in Great Britain November 6,1929.

;.. is in its assembled position.

According to one feature of the invention there is provided a selectorswitch in which the bank portion and selector portion are built up inthe form of separate units, the selector unit being dctachably mountedon the bank unit and being automatically secured thereto on assembly.

Preferably the construction is such that the rotation of the selectorunit as a whole r about the axis of the wiper shaft after as sembly isadapted to allow such unit to be removed from the bank unit.

According to a further feature there is pr vided a selector switch inwhich the selector unit adjustably mounted with respect to the contactbank in such a way that the selector unit after being adjusted withrespect to the contact bank may be completely removed therefrom andreplaced in its adjusted position without any further adjustingoperation being necessary.

According to a further feature there is provided a selector switchcomprising a bank frame and a selector frame in the form of naft O bani:frame which is cen respect to the contour of the contact bank.

- 1t arranged that the engagecf the selector with the support on thebank frame operates a lock ing device which holds said selector inposition on the bank frame.

According to a further feature, there is provided a selector switch inwhich the selector unit is adjusted with respect to the contact bank bymeans of a screw or the like and is locked its adjusted position bymeans of a single clamping device.

According to a further feature, there is provided a selector switch inwhich the feeder wipers are located on a frame which carries theselector wipers and is separate from the frame carrying the bankcontacts. The se lector frame is detachable from the bank frame so thatwhen the frame carrying the selector wipers is removed from the framecarrying the bank contacts the aforementioned feeder wipers are alsoremoved with the selector frame as one complete unit.

According to another feature there is provided a wiper which is verylight in weight and which is at the same time of sufficient strength forthe purpose required.

According to the invention a wiper is provided which is constructed froma metal pressing of channel formation.

The wiper may be of the double-arm variety the portion intermediate thearms being slightly enlarged so as to include the means for supportingthe wiper on the shaft of the switch mechanism. The channel formation isthen arranged to extend around this enlarged portion and along the sidesof the wiper arm. By this construction it will be seen that the wipermay be formed from a piece of thin sheet metal, but owing to the channelformation, it will have the necessary amount of rigidity for the purposerequired.

The wiper tips which preferably consist of one or more tongues may beformed from springy metal and may either be formed integrally with thewiper arms or may be rigidly secured thereto by welding or othersuitable means.

Thus it will be seen that the wiper including the tips may be formedfrom a single piece of metal, or the tips may be manufac turedseparately from a metal having the required amount of elasticity, andmay then frame and contacts of the switch with the" selector removedwhilst Fig. 1 shows a perspective view of the elector mechanism detachedfrom the bank frame 7 Figs. 5 and 6' show perspective views of a singledouble-arm wiper as embodied in the invention.

Referring now to these drawings, it will be seen that the switch isbuilt up in the form of two separate frames, the first frame 1hereinafter called the bank frame is shown by itself in Fig. 3 andsupports the bank contacts 3 and the feeder terminals 4. The secondframe 2, hereinafter called the selector frame and shown in Fig. 4detached from the bank frame, supports the selector wipers 5, theoperating magnet 6 together with its necessary transmission gear andalso the feeder wipers 7 The main advantages of the invention re side inthe facilities of assembling the two frames together and disassemblingthe frames from each other and in the simple form of adjustment wherebythe selector wipers may be adjusted to their desired posi tion withrespect to the bank contacts and whereby after such position has been atained, the frames may be disassembled from each other and may bereassembled into such a position that the aforementioned adjustment isnot disturbed. It is thought therefore that the invention will be bestunderstood by a description of the method by which the two frames areassembled and disassembled to and from each other, and of the adjustingarrangement referred to above.

Consider first. therefore, the switch with the two frames disassembledfrom each other as in Figs. 3 and 4. It will be seen that the bank frame1 is provided at one end with an extension plate 8 having a pair of lugs9 ar ranged one at each side each having a pin 10 extending therefrom.The feeder terminals 4 are connected to a plurality of spring clips 11which are arranged on the bank frame 1 in the form of a spring jackarrangement. Referring now to Fig. l, it will be seen that the selectorframe 52 carries at one end the axle of the selector bearing the wipersand ratchet wheel etc., and that the frame is provided with a shoulder12 carrying the operating magnet 6. The extremity of the selector frame2 is constructed in the form of an end plate 13 carrying the necessaryadjusting mechanism which will be described hereinafter. and a pluralityof slots ll arranged in the extremity of the frame in a plane at rightangles to the end plate 13. Bassing through the end plate 13 is anadjustingscrew 15 which is retained in any desired position by means ofthe nut 16. This adjusting screw 15 is of hollow formation in order toallow a further screw 17 to be loosely housed therein, this latter screwbeing prevented from falling through the adjusting screw 15 by means ofits head 18 whicn is of larger cross-section than the head of the adjusting screw 19. A washer 29 may also be inserted between the two headsif desired.

Consider now the assembling of the two frames 1 and 2 toget ier. Theselector frame 2 is placed with the ends of the slots 1% over the pins10 on the bank frame 1 and these slots are pressed down over the pins 10as far as is allowed by the adjusting screw 15, which (after a certainperiod) will be brought up against the end plate 8 of the bank frame 1.The selector frame 2 is now swung about the pins 10 as a pivot and theframe is'so constructed that when it is swan in this fashion the axle 20of the sele t-or will engage with "the slots 21 provided on the bankframe 1. A tached to the bank frame 1 by means of a leaf spring 22 is acatch or detent 23. Before the selector frame is placed in position onthe bank frame, the nose 2 1 of this catch or dctent 23 will be heldover the slot 21'by means of the force exerted by the leaf spring 22. ltif of course to be understood that a si catch or detent is provided oneach side of the bank frame since a slot is also provided on each sideof the frame in order to receive each end of the axle of the selector.the selector frame is swung into such a position that the ends of theaxle 20 with the slots 21, the selector frame is pushed dow a into theslots 21 so that the ends of the l 20 slide past the nose 241 of thedeternt nrt the same out of the way and slide into the bottom of theslots 21 whereupon the detents 23 fall back into their normal by virtueof the springs 22 so that the noses 24 fall over the axle 20 therebysecuring the latter to the bank frame. The adjustment of the selectorwipers with respect to the haul; contact is now carried out by means orbe adjusting screw 15 since when this is turned in either direction theextrem by of lector frame 2 can be correspondingly moved with respect tothe end plate 8 of the ban-l; frame,v whereupon selector wipers will berotated a corresponding distance over the bank contacts. 1 hen thedesired position is reached the wipers are correctly centered on a bankterminal set the locking screw 1'? is screwed down into the threadedhole 20 Eli provided therefor in the end plate 8 of the bank frame 1.The selector frame is now locked in its adjusted position and is firmlysecured to the bank frame 1.

As has before been mentioned, the feeder wipers 7 are located on theselector frame 2, and these are arranged at one end to make contact withthe selector wipers 5. The other ends of thee feeder wipers 7 areconstructed in the form of aplurality of knives 26 which on the assemblyof the two frames together are adapted to slide into the spring clips 11provided on the bank frame 1, thereby making contact with the feederterminals 4:.

The method of disassembling the selector frame from the bank frame willnow be de scribed. As will be seen hereinafter, the only operation whichis necessary to enable the selector frame to be removed from the bankframe is the removal of the loc ring screw 17 from the threaded hole 25in the plate 8. Attached to the selector frame 2 on each side of theframe is an arm 27 which is rigidly secu ed to the frame by means ofbolts or screws 28.

It will be seen that when the selector frame is in position on the bankframe, this arm 27 is located immediately under the nose 2 on the detent23. Thus it will be seen that after the locking screw 17 is removed fromthe threaded hole 25, if the whole selector frame 2 is rotated about theaxle 20 of the selector as a pivot, the arms 27 wil lift up the dctentsthereby enabling the selector aXle 20 to be withdrawn from the slots 21.

It will be seen that in removing the selector frame from the bank framethe adjustment of the selector wipers by means of the screw 15 has notbeen disturbed, since this latter screw remains in its adjustedposition. Thus the selector frame can be again replaced in position onthe contact frame in exactly the same position without furtheradjustment of the selector wipers being necessary since the position ofthose wipers with respect to the bank contacts will be exactly the sameas that which they left when the selector frame was removed.

Referring to Fig. 5 the wiper is constructed from a metal pressing 31which is of channel formation having a flange 32 around its edge. Itwill be seen that the central portion of the wiper intermediate thewiper tips 33 is slightly enlarged in order to include the aperture 3 1through which the selector shaft is adapted to pass. It will be seenthat the flange on the edge of the wiper is arra ged to extendcontinuously around the enlarged central portion and along the arms ofthe *iper in order to provide a sufficientl rigid structure.

It will be seen that in Fig. 5 the wiper tips 33 having one or moretongues 35, 36 are formed integrally with the arms of the wiper thisconstruction having the advantage that the Whole wiper together with thetips may be constructed from a single piece of metal.

It is at once obvious that the wiper tips which are arranged at an angleto the wiper arms must have a considerable amount of elasticity in orderto make proper contact with the bank terminals. It is, however, notessential that the remaining portion of the wiper should possess thesame degree of elasticity and an arrangement is shown in Fig. 6 in whichthe wiper tips instead of being formed integrally with the wiperarms'are constructed separately and subsequently welded or rivetted tothe ends of the wiper arms as shown. This construction has the advantagethat while the major portion of the wiper may be constructed from acomparatively soft metal, the wiper tips may still be formed from amaterial having the requisite amount of elasticity.

It is of course obvious that other forms of wiper tip may be employedwithout departing from the principle of the invention. For example eacharm may be provided with a pair of spring tips comprising one or morecontacting tongues, each tip being arranged so as to grip the bankcontacts on either side, in which case the two tips might be welded orotherwise secured to the same or opposite sides of the end portion ofthe wiper arm.

It will thus be seen that by means of the invention a selector switchhas been designed in which the bank construction and the selectormechanism are built up in the form of two separate and complete unitswhich may be readily attached to or detached from each other without theadjustments which have previously been effected being in any waydisturbed. At the same time an exceedinglv light wiper has been providedwhich by virtue of the channel formation is given the necessary amountof rigidity for the purpose required.

lVh at is claimed is:

l. A selector switch comprising in combination a frame having an.arcuate bank of contacts and a bearing centrally disposed with respectto said contacts, a subframe having a wiper sh ft and wipers mountedthereon for COOpcl tion with said contacts, means for securin said wipershaft in said bearing and means I01 locking said sub-frame to saidframe.

2. A selector switch comprising in combination a frame having an arcuatebank of contacts and a bearing centrally disposed with respect to saidcontacts, a sub-frame having a wiper shaft and wipers mounted thereonforcooperation with said contacts. means for seein said wiper shaft in saidhearing, means for adjusting said sub-frame relatively to said frameabout the axis of said wiper shaft and means for locking said subframeto said frame.

3. A selector switch comprising in combination a frame having an arcuatebank of contacts and a bearing centrally disposed with respect to saidcontacts, a sub-frame having a wiper shaft and wipers mounted thereonfor cooperation with said contacts, cooperating guiding means on saidframe and sub-frame remote from said bearing and wiper shaft, saidguiding means constituting a pivot about which the sub-frame may beswung to bring the wiper shaft into engagement with said bearing.

4. A selector switch comprising in combination a frame having an arcuatebank of contacts and at least one substantially radial open ended slotcentrally disposed with respect to said contacts, a sub-frame carryingwipers for cooperation with said contacts, a projection on saidsub-frame to engage said slot and locking means adapted to engage saidprojection.

5. A selector switch comprising in combination a frame having an arcuatebank of contacts and at least one substantially radial open ended slotcentrally disposed with respect to said contacts, a spring latch devicemounted adjacent said slot and adapted to close the open end thereof, asub-frame carrying wipers for cooperation with said contacts, aprojection on said sub-frame adapted to engage said slot and means onsaid subframe adapted to engage said latch device to release it fromsaid projection by relative rotational movement between the sub-frameand frame. 6. A selector switch comprising in combination a frame havingan arcuate bank of contacts, a sub-frame comprising driving mechanismand wipers for cooperation with said contacts, guiding means adapted tolo cate said sub-frame with respect to said frame and a self-lockingdevice adapted to secure the sub-frame in position on said frame.

7. A selector switch comprising in combination a frame having an arcuatebank of contacts, a sub-frame comprisin driving mechanism and wipers forcooperation with said contacts, guiding means adapted to lo cate saidsub-frame with respect to said frame, a self-locking device adapted tosecure the sub-frame in position on said frame and means cooperatingwith said self locking device and adapted to release the same byrelative movement between said sub-frame and said frame.

8. A selector switch comprising in combination a frame supporting anarcuate bank of contacts, a sub-frame detachably mounted on said frame,wipers rotatably mounted on said sub-frame and adapted to engage saidcontacts, stationary feeder wipers also mounted on said sub-frame andengaging said rotatably mounted wipers and contact devices mounted onsaid frame and adapted to connect with said feeder wipers.

9.v A selector switch comprising a frame, an arcuate bank of contactssupported by said frame, a sub-frame detachably mounted on said frame,wipers rotatably mounted in said sub-frame each of said wiperscomprising a light rigid portion constituted by a flanged sheet metalstrip, and a flexible tip portion for engagement with said contacts, anddriving mechanism for said wipers also mounted on said sub-frame;

10. A selector switch comprising in combination a frame having anarcuate bank of contacts and a centrally disposed bearing, a sub-framehaving rotatable wipers and driving mechanism mounted thereon and meanscoaxial with the rotatable axis of said wipers for engaging saidbearing,-locking means for securing said sub-frame to said frame andadjusting means independent of said locking means for adjusting theposition of said subframe relatively to said frame wherecy the sub-framemay be removed from and replaced on said frame in a pre-adjustedposition.

11. A selector switch comprising in combination a frame having onarcuate bank of contacts, a sub-frame having rotatable wipers anddriving mechanism therefor mounted thereon, a spring catch device onsaid frame adapted to engage a projection in said subframe to locatesaid wipers centrally with respect to said contacts and locking meansfor securing the sub-frame to the frame.

12. In a rotary step-by-step selector switch the combination of a bankportion, a selector portion, a pivotal connection between said portionscoincident with the rotational axis of the switch and a second pivotalconnection between said portions radially disposed near the outerperiphery of said bank portion, said second pivotal connection servingas a fulcrum for the selector portion in assembling the switch.

13. A selector switch comprising in combination, a frame adapted tosupport an arcuate bank of contacts and a bearing centrally disposedwith respect to said contacts, a sub-frame having a rotatable selectingelement for cooperation with said contacts and driving means therefor,means comprising a pin-and-slot connection and a spring catch forautomatically locating said sub-frame with respect to said frame andmeans for etachably securing said sub-frame to said frame.

14c. A selector switch comprising a frame adapted to support an arcuatebank of contacts and having a bearing centrally disposed with respect tosaid contacts, a subframe, means on said sub-frame for engaging saidbearing, driving mechanism and wipers supported by said sub-frame andmeans comprising cooperating pin-and-slot connections on said frame andsub-frame respectively and an adjustable stop for detachiell ablysecuring the two frames together in pro-adjusted relation.

15. In a rotary step-by-step selector switch the combination of a bankportion, aselector portion comprising a sub-frame carrying rotatablymounted wipers and driving mechanism therefor and means comprising twoseparated pivotal connections for connecting the selector portion to thebank portion, one of said pivotal connections being coaxial with therotatable axis of said wipers and the other of said pivotal connectionsbeing adjacent the outer periphery of said bank portion, the arrangementbeing such that the selector portion may be swung about one of saidpivotal connections when connecting it to the bank portion and about theother of said pivotal connections when disconnecting it therefrom.

16. In a rotary step-by-step selector switch the combination of a mainframe for supporting an arcuate bank of contacts, a sub-frame forsupporting the wipers and driving mechanism therefor, a pivotalconnection between said main frame and said sub-frame coincident withthe rotational axis of said wipers and means for adjustably securingsaid sub-frame in position about said pivotal connection.

17. In a rotary step-by-step selector switch the combination of a bankportion, a selector portion comprising a sub-frame carrying rotatablymounted wipers and driving mechanism therefor, means comprising twoseparated pivotal connections for detachably connecting the selectorportion to the bank portion one of said pivotal connections beingcoaxial with the rotative axis of said wipers and the other of saidpivotal connections being adjacent the outer periphery of said bankportion, and locking means associated with said connections for securingsaid portions together.

In witness whereof, We hereunto subscribe our names this 18th day ofSeptember, 1930.

CHARLES PERCY SMITH. GEOFFREY NEWTON.

